iOS实现带指引线的饼状图效果（不会重叠）

@interface DVFoodPieModel : NSObject/** 名称 */@property (copy, nonatomic) NSString *name;/** 数值 */@property (assign, nonatomic) CGFloat value;/** 比例 */@property (assign, nonatomic) CGFloat rate;@end

@interface DVPieCenterView : UIView @property (strong, nonatomic) UILabel *nameLabel; @end

@interface DVPieCenterView ()@property (strong, nonatomic) UIView *centerView;@end@implementation DVPieCenterView- (instancetype)initWithFrame:(CGRect)frame { if (self = [super initWithFrame:frame]) {  self.backgroundColor = [[UIColor whiteColor] colorWithAlphaComponent:0.4];  UIView *centerView = [[UIView alloc] init];  centerView.backgroundColor = [UIColor whiteColor];  [self addSubview:centerView];  self.centerView = centerView;  UILabel *nameLabel = [[UILabel alloc] init];  nameLabel.textColor = [UIColor colorWithRed:51/255.0 green:51/255.0 blue:51/255.0 alpha:1];  nameLabel.font = [UIFont systemFontOfSize:18];  nameLabel.textAlignment = NSTextAlignmentCenter;  self.nameLabel = nameLabel;  [centerView addSubview:nameLabel]; } return self;}- (void)layoutSubviews { [super layoutSubviews]; self.layer.cornerRadius = self.frame.size.width * 0.5; self.layer.masksToBounds = true; self.centerView.frame = CGRectMake(6, 6, self.frame.size.width - 6 * 2, self.frame.size.height - 6 * 2); self.centerView.layer.cornerRadius = self.centerView.frame.size.width * 0.5; self.centerView.layer.masksToBounds = true; self.nameLabel.frame = self.centerView.bounds;}

@interface DVPieChart : UIView/** 数据数组 */@property (strong, nonatomic) NSArray *dataArray;/** 标题 */@property (copy, nonatomic) NSString *title;/** 绘制方法 */- (void)draw;@end

- (void)draw { [self.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)]; [self setNeedsDisplay];}

CGFloat min = self.bounds.size.width > self.bounds.size.height ? self.bounds.size.height : self.bounds.size.width;CGPoint center = CGPointMake(self.bounds.size.width * 0.5, self.bounds.size.height * 0.5);CGFloat radius = min * 0.5 - CHART_MARGIN;CGFloat start = 0;CGFloat angle = 0;CGFloat end = start;

```objcif (self.dataArray.count == 0) {} else {}```* 当dataArray的长度为0时```objcif (self.dataArray.count == 0) {  end = start + M_PI * 2;  UIColor *color = COLOR_ARRAY.firstObject;  UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:start endAngle:end clockwise:true];  [color set];  //添加一根线到圆心 [path addLineToPoint:center]; [path fill]; }```> COLOR_ARRAY是自己设定的一个宏定义，产品要求的饼图份数是6份，每份颜色一定，所以做一个宏定义存储一下（做成变量都是可以的，看自己代码风格）``` objc#define COLOR_ARRAY @[/

```objcfor (int i = 0; i < self.dataArray.count; i++) { DVFoodPieModel *model = self.dataArray[i]; CGFloat percent = model.rate; UIColor *color = COLOR_ARRAY[i % 6]; start = end; angle = percent * M_PI * 2; end = start + angle; UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:start endAngle:end clockwise:true]; [color set]; //添加一根线到圆心 [path addLineToPoint:center]; [path fill];}```

* 在扇形绘画出来后，添加centerView```objc// 在中心添加labelDVPieCenterView *centerView = [[DVPieCenterView alloc] init];centerView.frame = CGRectMake(0, 0, 80, 80);CGRect frame = centerView.frame;frame.origin = CGPointMake(self.frame.size.width * 0.5 - frame.size.width * 0.5, self.frame.size.height * 0.5 - frame.size.width * 0.5);centerView.frame = frame;centerView.nameLabel.text = self.title;[self addSubview:centerView];```

// 获取弧度的中心角度CGFloat radianCenter = (start + end) * 0.5;// 获取指引线的终点CGFloat lineStartX = self.frame.size.width * 0.5 + radius * cos(radianCenter);CGFloat lineStartY = self.frame.size.height * 0.5 + radius * sin(radianCenter);CGPoint point = CGPointMake(lineStartX, lineStartY);

@interface DVPieChart ()@property (nonatomic, strong) NSMutableArray *modelArray;@property (nonatomic, strong) NSMutableArray *colorArray;@end

NSMutableArray *pointArray = [NSMutableArray array];NSMutableArray *centerArray = [NSMutableArray array];self.modelArray = [NSMutableArray array];self.colorArray = [NSMutableArray array];for (int i = 0; i < self.dataArray.count; i++) { DVFoodPieModel *model = self.dataArray[i]; CGFloat percent = model.rate; UIColor *color = COLOR_ARRAY[i]; start = end; angle = percent * M_PI * 2; end = start + angle; UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:start endAngle:end clockwise:true];  [color set]; //添加一根线到圆心 [path addLineToPoint:center]; [path fill]; // 获取弧度的中心角度 CGFloat radianCenter = (start + end) * 0.5; // 获取指引线的终点 CGFloat lineStartX = self.frame.size.width * 0.5 + radius * cos(radianCenter); CGFloat lineStartY = self.frame.size.height * 0.5 + radius * sin(radianCenter); CGPoint point = CGPointMake(lineStartX, lineStartY); if (i <= self.dataArray.count / 2 - 1) {  [pointArray insertObject:[NSValue valueWithCGPoint:point] atIndex:0];  [centerArray insertObject:[NSNumber numberWithFloat:radianCenter] atIndex:0];  [self.modelArray insertObject:model atIndex:0];  [self.colorArray insertObject:color atIndex:0]; } else {  [pointArray addObject:[NSValue valueWithCGPoint:point]];  [centerArray addObject:[NSNumber numberWithFloat:radianCenter]];  [self.modelArray addObject:model];  [self.colorArray addObject:color]; }}

- (void)drawLineWithPointArray:(NSArray *)pointArray centerArray:(NSArray *)centerArray

// 通过pointArray和centerArray绘制指引线[self drawLineWithPointArray:pointArray centerArray:centerArray];

- (void)drawLineWithPointArray:(NSArray *)pointArray centerArray:(NSArray *)centerArray { // 记录每一个指引线包括数据所占用位置的和（总体位置） CGRect rect = CGRectZero; // 用于计算指引线长度 CGFloat width = self.bounds.size.width * 0.5; for (int i = 0; i < pointArray.count; i++) {  // 取出数据  NSValue *value = pointArray[i];  // 每个圆弧中心店的位置  CGPoint point = value.CGPointValue;  // 每个圆弧中心点的角度  CGFloat radianCenter = [centerArray[i] floatValue];  // 颜色（绘制数据时要用）  UIColor *color = self.colorArray[i % 6];  // 模型数据（绘制数据时要用）  DVFoodPieModel *model = self.modelArray[i];  // 模型的数据  NSString *name = model.name;  NSString *number = [NSString stringWithFormat:@"%.2f%%", model.rate * 100];  // 圆弧中心点的x值和y值  CGFloat x = point.x;  CGFloat y = point.y;    // 指引线终点的位置（x, y）  CGFloat startX = x + 10 * cos(radianCenter);  CGFloat startY = y + 10 * sin(radianCenter);    // 指引线转折点的位置(x, y)  CGFloat breakPointX = x + 20 * cos(radianCenter);  CGFloat breakPointY = y + 20 * sin(radianCenter);    // 转折点到中心竖线的垂直长度（为什么+20, 在实际做出的效果中，有的转折线很丑，+20为了美化）  CGFloat margin = fabs(width - breakPointX) + 20;    // 指引线长度  CGFloat lineWidth = width - margin;    // 指引线起点（x, y）  CGFloat endX;  CGFloat endY;    // 绘制文字和数字时，所占的size（width和height）  // width使用lineWidth更好，我这么写固定值是为了达到产品要求  CGFloat numberWidth = 80.f;  CGFloat numberHeight = 15.f;    CGFloat titleWidth = numberWidth;  CGFloat titleHeight = numberHeight;    // 绘制文字和数字时的起始位置（x, y）与上面的合并起来就是frame  CGFloat numberX;// = breakPointX;  CGFloat numberY = breakPointY - numberHeight;    CGFloat titleX = breakPointX;  CGFloat titleY = breakPointY + 2;      // 文本段落属性(绘制文字和数字时需要)  NSMutableParagraphStyle * paragraph = [[NSMutableParagraphStyle alloc]init];  // 文字靠右  paragraph.alignment = NSTextAlignmentRight;    // 判断x位置，确定在指引线向左还是向右绘制  // 根据需要变更指引线的起始位置  // 变更文字和数字的位置  if (x <= width) { // 在左边      endX = 10;   endY = breakPointY;      // 文字靠左   paragraph.alignment = NSTextAlignmentLeft;      numberX = endX;   titleX = endX;     } else { // 在右边      endX = self.bounds.size.width - 10;   endY = breakPointY;      numberX = endX - numberWidth;   titleX = endX - titleWidth;  }      if (i != 0) {      // 当i!=0时，就需要计算位置总和(方法开始出的rect)与rect1(将进行绘制的位置)是否有重叠   CGRect rect1 = CGRectMake(numberX, numberY, numberWidth, titleY + titleHeight - numberY);      CGFloat margin = 0;      if (CGRectIntersectsRect(rect, rect1)) {    // 两个面积重叠    // 三种情况    // 1. 压上面    // 2. 压下面    // 3. 包含    // 通过计算让面积重叠的情况消除    if (CGRectContainsRect(rect, rect1)) {// 包含          if (i % self.dataArray.count <= self.dataArray.count * 0.5 - 1) {      // 将要绘制的位置在总位置偏上      margin = CGRectGetMaxY(rect1) - rect.origin.y;      endY -= margin;     } else {      // 将要绘制的位置在总位置偏下      margin = CGRectGetMaxY(rect) - rect1.origin.y;      endY += margin;     }              } else { // 相交          if (CGRectGetMaxY(rect1) > rect.origin.y && rect1.origin.y < rect.origin.y) { // 压在总位置上面      margin = CGRectGetMaxY(rect1) - rect.origin.y;      endY -= margin;           } else if (rect1.origin.y < CGRectGetMaxY(rect) && CGRectGetMaxY(rect1) > CGRectGetMaxY(rect)) { // 压总位置下面      margin = CGRectGetMaxY(rect) - rect1.origin.y;      endY += margin;     }         }   }   titleY = endY + 2;   numberY = endY - numberHeight;         // 通过计算得出的将要绘制的位置   CGRect rect2 = CGRectMake(numberX, numberY, numberWidth, titleY + titleHeight - numberY);      // 把新获得的rect和之前的rect合并   if (numberX == rect.origin.x) {    // 当两个位置在同一侧的时候才需要合并    if (rect2.origin.y < rect.origin.y) {     rect = CGRectMake(rect.origin.x, rect2.origin.y, rect.size.width, rect.size.height + rect2.size.height);    } else {     rect = CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height + rect2.size.height);    }   }     } else {   rect = CGRectMake(numberX, numberY, numberWidth, titleY + titleHeight - numberY);  }  // 重新制定转折点  if (endX == 10) {   breakPointX = endX + lineWidth;  } else {   breakPointX = endX - lineWidth;  }    breakPointY = endY;  //1.获取上下文  CGContextRef ctx = UIGraphicsGetCurrentContext();  //2.绘制路径  UIBezierPath *path = [UIBezierPath bezierPath];  [path moveToPoint:CGPointMake(endX, endY)];  [path addLineToPoint:CGPointMake(breakPointX, breakPointY)];  [path addLineToPoint:CGPointMake(startX, startY)];  CGContextSetLineWidth(ctx, 0.5);  //设置颜色  [color set];  //3.把绘制的内容添加到上下文当中  CGContextAddPath(ctx, path.CGPath);  //4.把上下文的内容显示到View上(渲染到View的layer)(stroke fill)  CGContextStrokePath(ctx);  // 在终点处添加点(小圆点)  // movePoint，让转折线指向小圆点中心  CGFloat movePoint = -2.5;  UIView *view = [[UIView alloc] init];  view.backgroundColor = color;  [self addSubview:view];  CGRect rect = view.frame;  rect.size = CGSizeMake(5, 5);  rect.origin = CGPointMake(startX + movePoint, startY - 2.5);  view.frame = rect;  view.layer.cornerRadius = 2.5;  view.layer.masksToBounds = true;  //指引线上面的数字  [name drawInRect:CGRectMake(numberX, numberY, numberWidth, numberHeight) withAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:9.0], NSForegroundColorAttributeName:color,NSParagraphStyleAttributeName:paragraph}];    // 指引线下面的title  [number drawInRect:CGRectMake(titleX, titleY, titleWidth, titleHeight) withAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:9.0],NSForegroundColorAttributeName:color,NSParagraphStyleAttributeName:paragraph}]; } }